Members of the Heracleum genus are hardy perennials that reach great heights of between 2.5 and 5.5 metres (8 to 17 feet).
They carry small white or pink flowers in umbels atop thick stems. They are ideal plants to grow in a wild flower garden or close to water.
Some common names for Heracleum include Cow Parsnip, Giant Hogweed, Cartwheel flower and Masterwort.
Heracleum sphondylium - Hog Weed by Mick E. Talbot.
Common Names: Hogweed, Giant Hogweed, Cow Parsnip, American Cow Parsley, Cartwheel Flower, Giant Masterwort.
Life Cycle: Hardy perennial.
Height: 110 to 144 inches (280 to 365 cm).
Native: Central Asia.
Growing Region: Zones 3 to 9.
When growing Cow Parsnips outdoors they should be prepared in the spring or autumn.
Spring sowing of Cow Parsnips is discussed here. The seeds should be sown in peat pots at a depth of 6 mm (1/4 inch) then the pots put in a black plastic bag, and placed in the the fridge for three weeks.
The pots should then be transferred and sank into a shady part of the garden, cover with glass.
Let the seedlings that appear grow until the autumn. Transplant the young Heracleum seedlings into a sunny or partially part of the garden. This should have a rich and moist soil.
As they are large plants, Heracleum should be spaced at about 1 to 1.25 m (40 to 50 inches) apart.
It is important to keep on top of Cow parsnips and other Heracleum Plants. They can spread rapidly and become invasive plants that will take over the garden given half a chance.
It is necessary to remove the flowering stems once they appear. Wear gloves when doing this as the leaves of the Heracleum plant are toxic, and may cause a skin rash. If you require more plants then they can be had by division, or just let them do their thing.
The Heracleum genus comprises about 60 species, notable for their large size and distinct flowering structures.
Some Heracleum species, such as Heracleum sphondylium or common hogweed, can make interesting additions to the garden but should be handled with care due to their sap.
Heracleum sphondylium is often grown, but its relative, the Giant Hogweed (Heracleum mantegazzianum), is notable for its massive size.
Many Heracleum species have a distinctive scent when their leaves or stems are crushed, but it is not generally considered fragrant.
Heracleum species prefer full sun to part shade and moist, fertile soil.
The Giant Hogweed (Heracleum mantegazzianum) is considered invasive in many parts of the USA, especially the Northeast, Midwest, and Pacific Northwest.
Removing Heracleum should be done with caution due to its phototoxic sap. It's recommended to use professionals for this task.
The Heracleum genus, part of the Apiaceae family, is made up of biennial and perennial herbs known as hogweeds. Native to temperate regions of the Northern Hemisphere, they are identified by their large, umbel-shaped flower clusters. Notable species include Heracleum sphondylium and Heracleum mantegazzianum.
Heracleum prefers full sun to partial shade and moist, well-drained soil. The plants are robust and can tolerate a wide range of conditions. Propagation is generally by seeds, sown in late summer to early fall.
I hope that you enjoyed this guide on how to grow Heracleum plants. You may also enjoy my gardening guides on how to grow Narcissus, Veltheimia plant, and Ixia plants.